Time course of heart rate during conditions. Time course of the average normalized heart rate curves of the 3 conditions. Thereby, the individual mean heart rate over the last minute of the warm-up phase (regular walking with 100% Guidance Force) served as an individual baseline (=100%) to which the longitudinal curves were normalized. The analysis shows that a steady state was reached after approximately 1 min and that the 1-min break was long enough for the heart rate to return close to baseline. (TIFF 1906 kb)